Class: RuboCop::Cop::Style::EmptyLiteral

Inherits:
Cop
  • Object
show all
Includes:
FrozenStringLiteral
Defined in:
lib/rubocop/cop/style/empty_literal.rb

Overview

This cop checks for the use of a method, the result of which would be a literal, like an empty array, hash or string.

Examples:

# bad
a = Array.new
h = Hash.new
s = String.new

# good
a = []
h = {}
s = ''

Constant Summary collapse

ARR_MSG = 
'Use array literal `[]` instead of `Array.new`.'.freeze
HASH_MSG = 
'Use hash literal `{}` instead of `Hash.new`.'.freeze
STR_MSG = 
'Use string literal `%<prefer>s` instead of ' \
'`String.new`.'.freeze

Constants included from FrozenStringLiteral

FrozenStringLiteral::FROZEN_STRING_LITERAL, FrozenStringLiteral::FROZEN_STRING_LITERAL_ENABLED, FrozenStringLiteral::FROZEN_STRING_LITERAL_TYPES

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from FrozenStringLiteral

frozen_string_literal_comment_exists?

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, parenthesized_call?, precede?, range_between, range_by_whole_lines, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, symbol_without_quote?, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, find_file_upwards, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

This class inherits a constructor from RuboCop::Cop::Cop

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 48

def autocorrect(node)
  lambda do |corrector|
    corrector.replace(replacement_range(node), correction(node))
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/empty_literal.rb', line 35

def on_send(node)
  add_offense(node, message: ARR_MSG)  if offense_array_node?(node)
  add_offense(node, message: HASH_MSG) if offense_hash_node?(node)

  str_node(node) do
    return if frozen_string_literals_enabled?

    add_offense(node,
                message: format(STR_MSG,
                                prefer: preferred_string_literal))
  end
end